Commonly, the static structure of a rotary apparatus of the type noted above includes an end plate, which has a cavity to accommodate a bearing race. It is convenient to refer to the cavity as a race cavity.
Commonly, the rotary structure thereof includes a main rotor and a stub shaft extending from one end of the main rotor, and the bearing includes an outer race seated in the race cavity of the end plate and an inner race having a central bore to accommodate the stub shaft, which is sized so as to be inserted into the central bore with a frictional fit. Commonly, the bearing is a rolling contact bearing including plural rolling elements interposed between the outer and inner races, as exemplified by a ball bearing.
Heretofore, it has been common for the outer race of the bearing to be press-fitted into the race cavity and for the stub shaft to be press-fitted into the central bore of the inner race by means of a hydraulic or mechanical press. Generally, it is satisfactory to employ a hydraulic or mechanical press to press the outer race properly into the race cavity, as it can be easily ascertained when the outer race has fully been pressed into the race cavity.
However, it is difficult to employ a hydraulic or mechanical press to press the stub shaft properly into the inner race, an it is necessary to provide a gap within a narrow range of tolerances (such as for example, 0.10 mm) between the main rotor and the end plate for proper operation of the rotary apparatus. It may then be necessary to employ gauges to assure a gap has been provided therebetween which falls within such a range.